Brisbane needs more water supplies so dam operators don't face a "Russian roulette situation" when deciding whether to release water ahead of floods, the city's mayor says.
Queensland's capital copped 795mm of rain - the city's wettest week since records began in 1840 - when deadly floods struck in February and March.
Thirteen people died and 18,000 homes and business were affected when multiple rivers broke their banks and flash floods surged through creeks across the state's southeast.
Operators of Wivenhoe Dam, Brisbane's main water supply, conducted a series of flood mitigation releases during the deluge, which critics claim intensified the flooding.
The state government is considering an independent report on its preparations for and management of the disaster, including dam management, handed to it last week.
Brisbane Lord Mayor Adrian Schrinner says the government should invest more in alternative water supplies so dam operators can proactively conduct flood releases.
He says it should be priority with another third consecutive La Nina event forecast this summer.
"So the dam operators have this really difficult position: they're preparing for drought on the one hand, hanging on to every bit of water they can, but they've also got to prepare for floods," he told ABC Radio on Tuesday.
"And if we had more reliable water sources, and invested in more water sources, then we wouldn't be in the situation where they've got this Russian Roulette situation, where it is: should we keep the water or should we release it in preparation for floods."
Water Minister Glenn Butcher brushed off the mayor's concerns, saying water supply compartments of major dams may be full, but the flood compartments are all empty.
He said dam controllers need guaranteed water supplies, and it's too early to know if flood releases will be needed this summer.
"Releasing water at an early stage now, and you know and rain doesn't turn up, then it'd be a different story," Mr Butcher told reporters.
"You know, we'd be looking at other options of saying well 'why was the water released when it didn't have to'."
The government is still considering a report on its preparations and management of the floods handed to them by the state's Inspector-General of Emergency Management last week.
Mr Butcher said he hadn't read the report, but suggested "there could be opportunities" to increase the capacity of flood compartments for some dams.
The Bureau of Meteorology said on Tuesday that southeast Queensland had received "average or above average rainfall" in August.
In the last seven days, rainfalls exceeded 100mm in parts of southern Queensland "which are usually dry this time of year", the forecaster said.
